:host {
  display: inline-flex;
  border: 2px dashed gray;
  padding: 2px;
}

/* 1. [Edge] no border on default slot */
.content ::slotted(*) {
  background-color: rgb(0, 255, 0);
}

/* 2. [Edge] extra border shows up on host */
::slotted(:not([slot="header-slot-name"])) {
  border: 4px solid rgb(0, 0, 255);
  color: rgb(0, 0, 255);
  font-weight: bold;
}

::slotted([slot="header-slot-name"]) {
  border: 4px solid rgb(255, 0, 0);
  color: rgb(255, 0, 0);
  font-weight: bold;
}

::slotted(*) {
  margin: 8px;
  padding: 8px;
}
